Testing is also carried out at estuarine sites – Pepe Inlet at Tairua, Whangamatā Harbour entrance, Whaingaroa Harbour near the motor camp and Maraetai Bay at Port Waikato.
Coastal and marine science team leader Dr Michael Townsend said as a rule, the water quality at Waikato region beaches is generally good for activities like swimming and surfing.
"But people should exercise caution for up to 48 hours following heavy rain, because it flushes contaminants from urban and rural land into waterways, which then make their way to the coast. These contaminants may be present in the water for up to two days after heavy or prolonged rainfall.
"Last summer we recorded two exceedances – at Buffalo Beach and Sunset Beach – and that's likely due to their proximity to large freshwater systems which will have been impacted by heavy rain."
He said providing the public with the best-quality information is important. "So we work together with district councils and Te Whatu Ora – Health New Zealand (Waikato) to identify any results that may have public health implications and then communicate them."
Te Whatu Ora Waikato's Medical Officer of Health, Dr Richard Wall, recommends that where public health warnings are in place, the water at these beaches should be avoided for all recreational use.
"If you do use the water for recreational purposes when a warning sign is in place, then you are potentially exposing yourself to harmful pathogens that can cause illnesses including gastroenteritis, respiratory illnesses, and ear and skin infections," Dr Wall said.
In addition to the coastal water quality testing, during summer the students will be sorting benthic macrofauna (sediment-dwelling organisms such as shellfish and marine worms), samples collected from estuaries and looking at the characteristics of the sediment to evaluate ecological health.